MAGNETIC RESONANCE IMAGING SCANNER

• US 20180081003A1
• Filed: 11/14/2017
• Published: 03/22/2018
• Est. Priority Date: 05/14/2015
• Status: Active Grant

• Current Assignee: Bilkent University
• Original Assignee: Bilkent University
• Inventors: Atalar, Ergin, Poni, Redi
• Granted Patent: US 10,641,847 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: G01R 33/3607 RF waveform generators, e.g. frequency generators, amplitude-, frequency- or phase modulators or shifters, pulse programmers, digital to analog converters for the RF signal, means for filtering or attenuating of the RF signal
• CPC Class Codes: G01R 33/3614 RF power amplifiers

Abstract

According to an embodiment of the present disclosure, disclosed is an apparatus for generating a radio frequency (RF) pulse in a magnetic resonance imaging (MRI) scanner. The apparatus for generating a radio frequency (RF) pulse in a magnetic resonance imaging scanner includes: a control module controlling a power amplifier and a signal generator; the signal generator configured to generate a signal of a predetermined waveform based on control by the control module and supply the generated signal of the predetermined waveform to the power amplifier in electromagnetic connection therewith; a power amplifier amplifying the signal supplied from the signal generator based on the control by control module and outputting the amplified signal to a coil; and the coil serving as an inductor of the power amplifier and transferring the amplified signal to the object so that an object is excited.

Claims

1. An apparatus for generating a radio frequency (RF) pulse in a magnetic resonance imaging (MRI) scanner, the apparatus comprising:

a control module controlling a power amplifier and a signal generator;

said signal generator configured to generate a signal of a predetermined waveform based on control by the control module and supply the generated signal of the predetermined waveform to the power amplifier in electromagnetic connection therewith;

said power amplifier amplifying the signal supplied from the signal generator based on the control by the control module and outputting the amplified signal to a coil; and

the coil serving as an inductor of the power amplifier and transferring the amplified signal to an object so that the object is excited.

2. The apparatus of claim 1, wherein the power amplifier comprises:

an input inductance component receiving power supplied from the signal generator,

a switching transistor controlled by the control module, and

one or more capacitors capable of storing electric charges.

3. The apparatus of claim 2, wherein the input inductance component is configured by a transmission line including a coaxial cable, and

the transmission line has a length so that impedance of the transmission line is the same as the impedance when the input inductance component is configured by a choke inductor.

4. The apparatus of claim 2, wherein the coil constitutes the capacitor of the power amplifier and an LC leg, and

the power amplifier serves as a class E power amplifier.

5. The apparatus of claim 1, wherein load resistance added to the power amplifier is a load added to the coil by the object and resistance of the coil.

6. The apparatus of claim 1, wherein the signal generator supplies a normal square waveform to the power amplifier.

7. The apparatus of claim 1, wherein the control module is configured based on an FPGA, generates a binary bitstream, and turns on or off the switching transistor of the power amplifier.

8. The apparatus of claim 7, wherein a period of a bit of each of binary bitstream signals generated by the control module is a half of a switching period of the power amplifier.

9. The apparatus of claim 7, wherein the control module determines parameters of a circuit by pre-scanning the circuit of the power amplifier and supplies the binary bitstream signal to the power amplifier based on the determined parameters.

10. The apparatus of claim 1, further comprising:

a converter electrically connecting the coil and the control module so as to transfer the signal transferred to the coil to the control module,

wherein the control module controls the power amplifier and the signal generator based on a feedback signal transferred through the converter.

11. A magnetic resonance imaging scanner comprising:

an RF pulse generating apparatus,

wherein the RF pulse generating apparatus comprises;

a control module controlling a power amplifier and a signal generator,

a signal generator configured to generate a signal of a predetermined waveform based on control by the control module and supply the generated signal of the predetermined waveform to the power amplifier in electromagnetic connection therewith,

said power amplifier amplifying the signal supplied from the signal generator based on the control by the control module and outputting the amplified signal to a coil, and

the coil serving as an inductor of the power amplifier and transferring the amplified signal to an object so that the object is excited.